1. Technical Field
The present invention relates in general to offshore drilling rig riser tensioners and, in particular, to an improved system, method, and apparatus for corrosion-resistant sleeves for riser tensioner cylinder rods.
2. Description of the Related Art
Some types of offshore drilling rigs utilize “push-up” or “pull-up” type riser tensioners. The riser tensioner incorporates cylinder rods to maintain tension on the riser. The cylinder rods are subjected to a very corrosive environment caused by exposure to drilling muds, completion fluids, and general offshore environments. As a result, the rods currently being used are made from either a solid nickel-based alloy or a laser-clad cobalt-based layer that is applied to a steel alloy rod. Both of these current rod options are expensive and, in the case of cladding, result in long lead times with multiple processes. Consequently, there is a higher probability for damaged parts and scrap or scrappage. Thus, an improved design for riser tensioner cylinder rods would be desirable.